[PATCH 07/27] Revert "drm/i915/gt: Propagate change in error status to children on unhold"

[Jason Ekstrand]

On Thu, Aug 19, 2021 at 1:22 AM Matthew Brost <matthew.brost at intel.com> wrote:
>
> Propagating errors to dependent fences is wrong, don't do it. A selftest
> in the following exposed the propagating of an error to a dependent
> fence after an engine reset.

I feel like we could still have a bit of a better message.  Maybe
something like this:

Propagating errors to dependent fences is broken and can lead to
errors from one client ending up in another.  In 3761baae908a (Revert
"drm/i915: Propagate errors on awaiting already signaled fences"), we
attempted to get rid of fence error propagation but missed the case
added in 8e9f84cf5cac ("drm/i915/gt: Propagate change in error status
to children on unhold").  Revert that one too.  This error was found
by an up-and-coming selftest which <salient information here>.

Otherwise, looks good to me.

--Jason

>
> This reverts commit 8e9f84cf5cac248a1c6a5daa4942879c8b765058.
>
> v2:
>  (Daniel Vetter)
>   - Use revert
>
> References: 3761baae908a (Revert "drm/i915: Propagate errors on awaiting already signaled fences")
> Signed-off-by: Matthew Brost <matthew.brost at intel.com>
> ---
>  drivers/gpu/drm/i915/gt/intel_execlists_submission.c | 4 ----
>  1 file changed, 4 deletions(-)
>
> diff --git a/drivers/gpu/drm/i915/gt/intel_execlists_submission.c b/drivers/gpu/drm/i915/gt/intel_execlists_submission.c
> index de5f9c86b9a4..cafb0608ffb4 100644
> --- a/drivers/gpu/drm/i915/gt/intel_execlists_submission.c
> +++ b/drivers/gpu/drm/i915/gt/intel_execlists_submission.c
> @@ -2140,10 +2140,6 @@ static void __execlists_unhold(struct i915_request *rq)
>                         if (p->flags & I915_DEPENDENCY_WEAK)
>                                 continue;
>
> -                       /* Propagate any change in error status */
> -                       if (rq->fence.error)
> -                               i915_request_set_error_once(w, rq->fence.error);
> -
>                         if (w->engine != rq->engine)
>                                 continue;
>
> --
> 2.32.0
>